Dryer for printed sheets



June 4, 1968 DRYER FOR PRINTED SHEETS 5 Sheets-Sheet l Filed June 22, 1966 lllllllll \\|l|l/ mllb m M n n Q n 1/ n I 6 Bg z 'l -mhwzh l. J M :zunwueTv n rl 7 u n n l|UUHW||I|||h.|| -I|J|l|\|L n w 'nln n m G .lmvllummln HHHI|I|ILUHI|F HH. n K 2 di a -Jell l|| 2/ Tl/ w Kw w ||v 13TT|||| m 7 fr! o. n 1.1L wn l 1-- Tor x .L/ 0A .--if N id f I| n. on o n u ||V. M4 1 1111 lll llllllll 7/ .||l||||l||lllllll||\|l. c M f 2 Q w 5 a J m 9 G M 1 8 I Mx INVENTOR. FLPH E DSE 5R,

June 4, 1968 R, a ROSE, SR 3,386,714

DRYER FOR PRINTED SHEETS Filed June 22, 1966 5 Sheets-Sheet 2 46 INVENTOR. 5+ FHLPH B. ROSE SR 197' TOF/UEX June 4, 1968 R- B. ROSE SR 3,386,714

DRYER FOR PRINTED SHEETS Filed June 22, 1966 5 Sheets-Sheet 3 United States Patent() 3,386,714 DRYER FOR PRINTED SHEETS Ralph B. Rose, Sr., 4370 SW. th St., Miami, Fla. 33134 Filed June 22, 1966, Ser. No. 559,582 Claims. (Cl. 263`8) The present invention relates generally to dryers and is more particularly directed to a. greatly improved dryer structure of the type commonly used to dry inks and various other pigments applied to the surfaces of posters, sign boards or the like.

The greatest problem in printing or sign shops where posters, signs or the like are produced by modern methods and machinery, such as by silk screen machines, is to provide means to dry the various inks and pigments applied to the surfaces of the posters and signs rapidly enough to keep pace with their production. The greater the area of ink or other pigment being applied to a particular sign or poster, the more difficult it becomes to dry the ink or pigment thoroughly to enable them to be safely stacked when emerging from the dryer.

At present it is common practice to utilize two, three or more dryers in a line with an appropriate conveyor transporting the signs or posters successively under each dryer to accomplish this thorough drying operation or, alternatively, extremely long dryers are utilized to the same end. Obviously, either method is quite expensive and requires a very considerable amount of floor space. Generally, present dryers of this type provide a continuous stream of warm air to pass over the surface to be dried; for example, the air may be heated by the heat exchange principle of simply passing it over the exterior of a heat chamber and being -directed at the surface to be dried through a multiplicity of apertures in a thin baille plate. After passing through the baille plate the warm air immediately merges into a continuous stream to pass over the surface to be dried.

One of the lprinciple objects of the instant invention is to provide a compact dryer for thoroughly drying surface applied inks or other pigments on signs, poster boards or the like such as are mass produced, for example, by a silk screen machine in accordance with their production rate.

Another object of the invention is to provide a compaot dryer to thoroughly dry surface inks and `other pigments applied to signs, poster boards or the like, over large areas with the same or greater efficiency than that accomplished by very large dryers or multiple groupings of smaller dryers in present use.

A still further object of the instant invention is to provide a dryer utilizing a multiplicity of elongated jets so arranged and positioned to direct individual streams of hot air under pressure to impinge upon every portion of the surface of signs or poster boards being conveyed 'V underneath the jets, closely adjacent thereto.

A further object of the invention is to provide a dryer utilizing `a suflicient number of elongated jets in communication with a pressure chamber to provide individual streams of hot air to impinge upon every portion of the surface to be dried two or more times.

Still another object of the invention is to provide a stream of air from a fresh air blower to the hot air pressure `chamber which is directed through the interior chamber of a lire box before entering the pressure chamber.

A still further object of the instant invention is the provision of `an exhaust blower to draw off unburned gases and vapors from a chamber where they gather after having impinged on the surface of the sign or poster to be dried, said exhaust blower being in communication with the fresh air blower.

Patented June 4, 1968 ICC For a better understanding of the instant invention, to gether with other `objects and advantages thereof, reference is made to the following description of the accompanying drawings, in which a preferred embodiment is illustrated.

In the accompanying drawings:

FIG. l is a front elevational view of the dryer of the instant invention, illustrating a conveyor transporting a sign or poster board into position to be dried;

FIG. 2 is a side elevational view of the dryer, taken along the line 2-2 of FIG. l and looking in the direction of the arrows;

FIG. 3 is a horizontal sectional view of the dryer taken along the line 3-3 of FIG. 2 and looking in the direction of the arrows;

FIG. 4 is `a vertical sectional View taken along the line 4 4 of FIG. 3 and looking in the direction of the arrows;

FIG. 5 is a vertical sectional View taken along the line 5--5 of FIG. 4 and looking in the direction of the arrows;

FIG. 6 is a horizontal sectional View taken along the line 6 6 of FIG. 5 and looking in the direction of the arrows;

FIG. 7 is an enlarged fragment-ary top plan view 0f a portion of the jet plate as seen in FIG. 6; and

FIG. 8 is a vertical sectional view taken along the line 8-8 of FIG. 7 and looking in the direction of the arrows.

Referring to the drawings in which arrowed lines indicate fluid flow and like reference numerals designate like or similar parts throughout, 10 indicates generally a table assembly over which a freshly printed or painted sign or poster board 12 is being transported by means of a conveyor 14 into the dryer unit in chief, indicated generally at 16, which comprises a fresh air` preheat chamber 18 including a preheat air supply blower 20 to blow the preheated air through a conduit 26 to a fire box 28 and ducts 30 and 32 from the lire box to a pressure chamber 34, the bottom of which comprises a jet plate 36 containing a multiplicity of jets 40 to direct streams of hot .air onto the surface of the freshly printed or painted sign as will be hereinafter described. The heated air is then exhausted under the influence of an exhaust blower 24 through a jacket or exhaust chamber 22 which at least partially surrounds the preheat chamber in heat exchanging relation therewith.

The supporting table assembly 1t) for tbe dryer is composed of four legs 46, front and back channels 48 and 50, a pair of side channels 52 and 54 and a bottom closure plate 56 fixed as by welding to the bottom webs of the front, back and side channels 48, 50, 52 and 54 as best illustrated in FIG. 4. The legs 46 are fixed to the corner intersections of the channel members as by rivets or bolts 58. As best illustrated in FIGS. 1, 2 and 4 the side channels being somewhat narrower vertically than the front and back channels 48 and 50, the plane of the top webs of the side channels are displaced below the plane of the top webs of the front and back channels to provide an appropriate shallow passageway 62 between the top of the table unit 10 and the bottom of the dryer unit 16 for passage of the top input run 64 of the conveyor 14. A series of tubular conveyor belt supports 66 are welded between the inside faces of the front and back channel members 48 and 50 to support the conveyor belts to maintain the article to be dried in a precise plane of travel as it passes under the dryer 16.

The dryer 16 comprises an Outer insulated housing 70 and an inner housing 72 to provide the exhaust jacket 22 therebetween (FIGS. 3, 4, and 5) to preheat incoming air and of which more will be written hereinafter. The outer housing is composed of a roof or top 74 and front and back Walls 76 and 78 preferably formed integral therewith. Likewise, the inner housing 72 provides a top 80 with front and back walls 82 and 84 formed integral therewith in inwardly spaced relation to the outer housing to form the space defining the exhaust jacket 22. As best illustrated in FIG. 4, the back wall 84 of the inner housing 80 is offset inwardly to provide an enlarged portion 86 in the exhaust chamber to accommodate the exhaust blower 24 having an intake opening 8S to the exhaust jacket 22 and an outlet or exhaust opening 90 to the atmosphere. An insulated pair of side walls 92 and 94 form a common end closure for both the outer and inner housings 70 and 72 as best illustrated in FIG. 3; however, the walls may not be in common planes to expand the preheat jacket. The lower distal ends of the front and back walls 82 and S4 of the inner housing are xed to the upper horizontal webs of the front and back channels d8 and 50 of the table 10 as at 96 and 98 by welding, while the lower distal ends of the front and back walls 76 and 78 of the outer housing extend downwardly in outwardly spaced relation to the channels 48 and 50 to provide inwardly turned flanges 100 and 102 fixed to the outer vertical faces of the channels 48 and 5() adjacent the lower edges thereof. Pairs of exhaust openings 104 and 106 in each of the front and back channels 48 and 50 provide for exhaust communication between the chamber 108 in the table beneath the input conveyor 64 and the exhaust chamber 22 in the housing to the exhaust blower 2d. As best illustrated in FIGS. 2 and 6, the conveyor 14 is preferably composed of a plurality of narrow belts spaced apart to provide access to the chamber 108 for the unburned gases and fumes from the jets which will be hereinafter described.

Adjacent the top of one side wall 92, a pair of fresh air inlet openings 110 and 112 are provided in communication with the fresh air chamber 18 which is deiined by the inner surface of the inner housing 72 and the side Walls 92 and 94. A baille plate 114 is utilized to direct the fresh air downwardly to be passed over the heated pressure chamber 34, to preheat the air before it is drawn into the intake 116 of the fresh air blower 20 contained within the fresh air chamber 12. From the blower 20, the fresh air is exhausted under pressure to the duct 2.6, in communication with the iire box 28 as at 120. A gas burner 122 which may be provided with a conventional pilot light and thermocouple 124 extends into the fire box 28 and is pressure fed by means of the motor driven pump indicated generally at 130. Appropriate access doors 131 and 132 to the fire box are provided in one side wall of the lire box and the side wall 94 of the dryer housing (FIG. 5).

The fresh air may be further preheated by providing a duct 133 communicating between the exhaust blower and the fresh air blower and by driving the fresh air blower at a somewhat higher rate of speed than the exhaust blower to draw off part of the heated exhaust to mix with the fresh air. The two blowers may be driven by any conventional means, not shown.

Referring to FIG. 5, from the fire box the hot air is exhausted through an appropriate outlet 134 in the top wall thereof, through horizontal duct 30 and vertical duct 32, into the pressure chamber 34 through an opening 135 in the top wall 136 thereof. Pressure chamber 34 also includes front and back walls 13S and 140, a pair of side walls 142 and 144 and a bottom wall or jet plate 36 and is mounted interior of the bottom portion of the fresh air chamber 18 to co-operate with the duct 26 to form a bottom closure for the fresh air chamber 18. As best illustrated in FIG. 6, the pressure chamber 3d spans the entire width of conveyor belts 64 to present the bottom jet plate 36 in a horizontal plane closely adjacent the top of the input run of the conveyor belts 64. A multiplicity of elongated jets 152 are provided in rows across the width of the jet plate 36, said rows being angled somewhat in relation to the parallel front and back walls 138 and 14() of the pressure chamber.

Referring now to FIGS. 7 and 8, the jets are preferably mounted in the jet plate 36 in a vertical position extending upwardly into the pressure chamber to present a smooth lbottom surface on the jet plate to preclude the possibility of articles passing closely adjacent thereunder, catching on the jets or jet plate. As previously stated, the rows of jets are angled to direct streams of air through the jet bores to encompass the entire surface of the sign or poster board to be dried. This is accomplished, by way of example, by spacing the rows of jets one inch apart and angled to a degree that lines 162 drawn parallel to the front and back walls 133 and 140 and tangent to the back curvature of bore 160 of one jet will be tangent to the front curvature of bore 160 of the next succeeding jet (FIG. 7). If the inner bore diameter is one-eighth of an inch, eight rows across from front 13S to back 140 will provide a direct stream of hot air to every portion of an article passing closely adjacent underneath the jets, by providing thirty-two rows from front to back, every portion of the article will be contacted by a direct jet stream of hot air four times.

The jets 152 are preferably of sutlicient length to pro` vide streams `of air to the surface of the article passing thereunder with little or no loss of velocity or increase in diameter or spread because it has been found that such streams of hot air literally scrub the ink or other pigment dry in a fraction of the time required to accomplish the same end by the conventional methods now 1n use.

As illustrated in FIG. 8, the jets are mounted in apertures 166 in the jet plate, preferably, by providing the same diameter for the apertures as the outer diameter of the jets 152, expanding the metal slightly about the lower diameter of the jets by vertical score lines, inserting the top of the jets into the apertures from the bottom of the jet plate and pressing them upwardly into a tight press fit as in FIG. 8. A cross brace 170 extending from the front 138 to the back 140 may be employed to support the mid portion of the jet plate 136.

While there has been illustrated and described what is considered to be a preferred embodiment of the instant invention, it will be obvious to those skilled in the art that various modifications may be made therein without departing from the true scope of the invention as defined by the appended claims.

I claim:

1. A dryer for use in heating air to dry inks or other pigments on a main surface of sheet material such as sign boards comprising:

an insulated housing including:

a bottom, roof and upstanding walls defining a closed interior having a main inlet opening above the bottom, said housing having an eX- tension below the outer surface of the bottom and said extension having an inlet mouth and an outlet opening immediately adjacent said bottom to dene a tunnel or passage for sheet material between the mouth and the outlet openlng;

conveyor means arranged to support a piece of sheet material on passage through the tunnel in close association to the bottom;

a divider wall to separate the interior into an upper and lower chamber between the divider wall and the roof and the divider wall and the bottom respectively;

a heated air path to connect the upper and lower chambers from the main inlet port in the upper chamber, said path including:

the upper chamber;

a re box in the upper chamber;

tirst duct means to connect the upper chamber to the tire box to llow preheated gases from the upper chamber to said re box;

second duct means in the upper chamber to connect an exhaust opening in an upper portion of the re box to the lower chamber; and

pump means in said path to force air therealong and to cause a pressure differential between the upper and lower chambers to draw fresh air into the upper chamber to be preheated and, thence, to force it through the fire box and second duct means to the lower chamber;

the bottom of said lower chamber comprising the roof of said tunnel of passage and said bottom including a plurality of openings deiining a pattern as seen in plan for the discharge of heated air into the tunnel of passage, said pattern being such that every portion of a sheet passing through the tunnel is constrained to passage below at least one of said openings; and

means arranged in the fire box to heat gases in the lire box.

2. A dryer as set forth in claim 1 wherein a vertically disposed jet is arranged in each of the openings of said bottom to provide a plurality of streams of hot air under pressure to impinge on the surface of the sheet confronting the bottom.

3. A dryer as set forth in claim 1 wherein said housing includes a septum to separate the housing interior into an inner chamber for fresh air to be heated and a separate outer chamber to partially jacket the inner chamber and the tunnel; and collector means to collect heated gases after impingement on a sheet to be dried passing through the tunnel, said collector means being connected to and constraining said exhaust gases to flow through the outer chamber to an exhaust port in said outer chamber.

4. A dryer as set forth in claim 3 wherein blower means is included in the outer chamber to draw air through the collector means and outer chamber.

S. A dryer as set forth in claim 4 wherein jet means are disposed in each of the openings of the bottom and arranged in columns and rows such that hot air under pressure is adapted to pass from the lower chamber to impinge on the entire surface of a sheet passing through the tunnel.

6. A dryer as set forth in claim 4 wherein a duct is provided to connect the inner chamber and the outer chamber and said pump means and said blower means are arranged such that said pump means moves a greater volume of air than said blower means to draw a portion of the heated exhaust gases into the preheat chamber.

7. A dryer as set forth in claim 3 wherein jet means are disposed in each of the openings of the bottom and arranged in columns and rows such that hot air under pressure is adapted to pass from the lower chamber to impinge on the entire surface of a sheet passing through the tunnel.

8. A dryer as set forth in claim 1 wherein a baille plate is arranged in the housing interior and arranged in the inner chamber adjacent the main inlet opening to direct incoming air to flow over the divider wall and around the lire box on passage from the main inlet opening to the lire box.

9. A dryer as set forth in claim 1 wherein diffuser means are arranged adjacent the juncture of the second duct means and in the lower chamber to disburse the incoming heated gases so that a relatively uniform and increased pressure is maintained in the lower chamber relative to that of the upper chamber.

10. A dryer as set forth in claim 1 wherein each of the openings includes jet means arranged therein and the pattern comprises a plurality of rows and columns as seen in plan with the composite diameters of the jets of the rows and the composite diameters of the jets of the columns such that on passage of a sheet to be dried through the tunnel heated air under pressure is directed through the jets directly onto imaginary lines connecting the diameters of the rows and columns and the imaginary lines cover the sheet as seen in plan.

References Cited UNITED STATES PATENTS 1,043,324 11/1912 Levison 263--8 2,471,802 5/ 1949 Walter et al. 34-160 2,981,528 4/1961 Culp 34-223 XR 3,060,595 10/ 1962 Dapses 34-233 XR 3,074,179 1/1963 Stelling s 34-160 3,312,811 4/ 1967 Shanklin 263--8 XR FOREIGN PATENTS 737,311 9/ 1955 Great Britain.

FREDERICK L. MATTESON, IR., Primary Examiner.

H. B. RAMEY, Assistant Examiner. 

1. A DRYER FOR USE IN HEATING AIR TO DRY INKS OR OTHER PIGMENTS ON A MAIN SURFACE OF SHEET MATERIAL SUCH AS SIGN BOARDS COMPRISING: AN INSULATED HOUSING INCLUDING: A BOTTOM, ROOF AND UPSTANDING WALLS DEFINING A CLOSED INTERIOR HAVING A MAIN INLET OPENING ABOVE THE BOTTOM, SAID HOUSING HAVING AN EXTENSION BELOW THE OUTER SURFACE OF THE BOTTOM AND SAID EXTENSION HAVING AN INLET MOUTH AND AN OUTLET OPENING IMMEDIATELY ADJACENT SAID BOTTOM TO DEFINE A TUNNEL OR PASSAGE FOR SHEET MATERIAL BETWEEN THE MOUTH AND THE OUTLET OPENING; CONVEYOR MEANS ARRANGED TO SUPPORT A PIECE OF SHEET MATERIAL ON PASSAGE THROUGH THE TUNNEL IN CLOSE ASSOCIATION TO THE BOTTOM; A DIVIDER WALL TO SEPARATE THE INTERIOR INTO AN UPPER AND LOWER CHAMBER BETWEEN THE DIVIDER WALL AND THE ROOF AND THE DIVIDER WALL AND THE BOTTOM RESPECTIVELY; A HEATED AIR PATH TO CONNECT THE UPPER AND LOWER CHAMBERS FROM THE MAIN INLET PORT IN THE UPPER CHAMBER, SAID PATH INCLUDING: THE UPPER CHAMBER; A FIRE BOX IN THE UPPER CHAMBER; FIRST DUCT MEANS TO CONNECT THE UPPER CHAMBER TO THE FIRE BOX TO FLOW PREHEATED GASES FROM THE UPPER CHAMBER TO SAID FIRE BOX; SECOND DUCT MEANS IN THE UPPER CHAMBER TO CONNECT AN EXHAUST OPENING IN AN UPPER PORTION OF THE FIRE BOX TO THE LOWER CHAMBER; AND PUMP MEANS IN SAID PATH TO FORCE AIR THEREALONG AND TO CAUSE A PRESSURE DIFFERENTIAL BETWEEN THE UPPER AND LOWER CHAMBERS TO DRAW FRESH AIR INTO THE UPPER CHAMBER TO BE PREHEATED AND, THENCE, TO FORCE IT THROUGH THE FIRE BOX AND SECOND DUCT MEANS TO THE LOWER CHAMBER; THE BOTTOM OF SAID LOWER CHAMBER COMPRISING THE ROOF OF SAID TUNNEL OF PASSAGE AND SAID BOTTOM INCLUDING A PLURALITY OF OPENINGS DEFINING A PATTERN AS SEEN IN PLAN FOR THE DISCHARGE OF HEATED AIR INTO A TUNNEL OF PASSAGE, SAID PATTERN BEING SUCH THAT EVERY PORTION OF A SHEET PASSING THROUGH THE TUNNEL IS CONSTRAINED TO PASSAGE BELOW AT LEAST ONE OF SAID OPENINGS; AND MEANS ARRANGED IN THE FIRE BOX TO HEAT GASES IN THE FIRE BOX. 